AuthorTopic: instant pace in gh-625xt (Read 10109 times)

Suggestion: Use pace since last lap and instant pace and your instinct together to adjust to correct pace.

+/- 5 sec/km is extremely narrow also with good GPS reception. Good accuracy is about 5m. Open fields and clear sky may give you down to 3m, a wood trail in rain maybe 8m, city canyon infinite. The accuracy is a mediate number, average is even higher. The error is not completely random. Back/forward errors will not affect distance, but left/right. For pace all errors affect though. With every second averaging, the speed could differ as much as -5 m in one point and +5 in next, which may give 0 speed in one point and 2 min/km in next. This is why the device uses smoothing to present pace. Since many users have a different opinion on "correctness" vs responsiveness, user option is a good thing.(and the 625XT GPS is better than most.)

Thank you all for your experiences/clarifications, which have helped me to understand that the problem is native in the GPStechnology and perhaps we can not expect much more in terms of GPS accuracy. I agree that user should be able to choose the level of smoothing which is closest to his liking, and as has already been mentioned by partyman66 would be nice to implement this option in the next firmware. I appreciated the tips about buying but I'm planning on using ebay that I normally use which gives me more reliability and security.

Don’t take any chances. Buy your GlobalSat products directly from DTech – a first tier distributor. all our products are brand new with latest edition firmware or software. Warranty – we provide 12 months warranty for all our products. We do not hide behind vague statements like “one year manufacturer” warranty that send the customer to deal directly with the manufacturers. We are standing behind the quality of our products and provide a direct warranty, repair and replacement service by us.

14 Days Money back warranty – If by any reason you are not pleased with the items purchased, you can return it to us in it’s original packaging within 14 Days from receiving the item. We will credit you PayPal account back immediately when we receive the product back. Please note that shipping cost from us and back to us is not refounded.

Warranty and repairsAll products are covered by full 12 months warranty from DTech.Warranty cards are included within product box.

So I think he's ok. Also before buying, I asked about the warranty, and the answer was: "there is no agent for Globalsat in Italy. If you have a problem / need warranty - you need to send it back to us in Israel or Taiwan for repair or replace. "

'Pace' and 'Speed' are not the same thing!Is an oddity of my unit or is a conscious choice?The speed showing in km/h seems to be an average of last 8-10 seconds and is fairly satisfactory, while the 'Pace' showing in min/km seems to be the result of an average of indefinite and much longer interval. I often run on routes where there are alternating ascending descending and flat sections, so in this kind of trails the "pace" is not useful to me.It would be useful to have also a real "instant pace" or be able to choose in which way the speed is expressed (km/h or min/km).

It would be useful to have also a real "instant pace" or be able to choose in which way the speed is expressed (km/h or min/km).

Hi,the Pace-discussion is one of the first features we discussed just when GH-615 was the actual model.The problem is the acuracy of GPS. Especially when speeds are slow (like 10 or 12 km/h) there are big errors if the speed is calculated from two geographical points which are aquired within some seconds. These two points will be near together if the real speed is slow. Every point will have an absolute error up to 10 m caused by the GPS-accuracy. There was the idea to calculate the Pace from the actual last 1000 m (called Pace1K-discussion) but at the end the GS-engineers managed to get a relative reliable value for pace, if the last 600 m were talken for pace-calgulation.Instant-Pace as function 1/Speed would work, if you run speeds around 20 km/h = 3min/km.

Try the following: Ride your bike with constant 15/20/25 km measured by bycile-computer and watch the speed which is shown by the Gps-watch. GPS-watch will jump in a range which is larger, the slower you ride.Certainly It would be fine to find a solution which eleminates the error caused by GPS-error at lower speeds but this would cost sensivityBest regards

Yes, but speed is certainly calculated by averaging over a shorter interval than 600m and I'm already quite satisfied with the "Speed" given by the watch, even at speeds lower than 20km/h. It would be nice to have a chance to see it also in "min*km" mode.

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canadien

Wow just made a test and am astonished how pace is so slow reactive. Looks more like an average than a real pace. Another reason for me to prefer speed over pace. I suppose it is specifically made for running and "speed" for faster activity, but Geoffrey once wrote that they removed errors tampon calculation that was on sirfstar3 devices because of sirstar4 precision. So i wonder why it is that much slow reactive.

Anyhow I would like to see the algorithm of both cause right now it seem that Wincent's request is totally valuable.

Do you think it would be feasible and satisfactory planning of workouts based on repeated intervals, alternating several times eg. 2km at a fast pace, and 1km at a slow pace, possibly by setting alarms when exceeding or coming off of 10 sec/km? or better 5 sec/km?

Suggestion: Use pace since last lap and instant pace and your instinct together to adjust to correct pace.

+/- 5 sec/km is extremely narrow also with good GPS reception. Good accuracy is about 5m. Open fields and clear sky may give you down to 3m, a wood trail in rain maybe 8m, city canyon infinite. The accuracy is a mediate number, average is even higher. The error is not completely random. Back/forward errors will not affect distance, but left/right. For pace all errors affect though. With every second averaging, the speed could differ as much as -5 m in one point and +5 in next, which may give 0 speed in one point and 2 min/km in next. This is why the device uses smoothing to present pace. Since many users have a different opinion on "correctness" vs responsiveness, user option is a good thing.(and the 625XT GPS is better than most.)

It seems impossible to create workout as when I asked info a few posts above.In the section: GYM> INTERVAL TRAINING> CREATE WORKOUT you can only create time-based intervals (RUN-TIME), or distance-based intervals (RUN-DIST), without regard of the speed to maintain, so it is impossible even set alarms when you are out of Pace/Speed range.Instead in (HEARTRATE) interval, you can set both the pulse-range and the time so the alarm occurs properly when you exit from the pulse-range.I wonder if the lack of functionality is also due to the aforementioned lack of sensitivity in the detection of the instantaneous speed.